reaction product of wheat aminoacids and lauryl chloride

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01.February.2008-04.November.2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline, GLP study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Reference item
Identity: Sodium benzoate
Batch number: 095K0681
Expiry date: September 2009
Purity: 100.3%
Certificate of analysis/date: September 2005
Empirical Formula / Molecular weight: C7H5O2Na / 144.10 g/mol
Theoritical Oxygen Demand: ThODNH4: 1.666 mg oxygen per mg sodium benzoate
Storage: In original container, at room temperature (10-30 °C), in the dark

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Inoculum Control: The oxygen demand of the inoculum control (medium and inoculum) was 27 mg O2/L and thus not greater than 60 mg O2/L within 28 days as required by the test guideline.
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Aerobic activated sludge, micro organisms from a domestic waste water treatment plant was supplied by the sewage plant Darmstadt, Germany.
- Laboratory culture: not applicable
- Method of cultivation: not applicable
- Storage conditions: During the holding period the sludge was aerated.
- Storage length: 2 days prior to use
- Pretreatment: The aerobic activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and centrifuged again. This procedure was done three times.
- Initial cell/biomass concentration: An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 1.5g dry material per litre were mixed with test water.
- Water filtered: no

Duration of test (contact time):

ca. 28 d

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Test System
Species/Origin: Aerobic activated sludge, micro organisms from a domestic waste water treatment plant was supplied by the sewage plant Darmstadt, Germany.
Conditioning: The aerobic activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and centrifuged again. This procedure was done three times. The sediment was re-suspended in test water and aerated for two days. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 1.5g dry material per litre were mixed with test water (see 6.5). This suspension was used for the experiment.

Test Units
Type and Size: Manometric Test System with test flasks containing a vol
ume of approximately 500 mL (see 6.8).
Apparatus: BSB Sensomat system, Aqualytic Langen
Principle: The test flasks prepared according paragraph 6.6 were incubated at 20 + 2 °C. The pressure decrease in the reaction vessels was measured over complete experimental phase of 28 days using the BSB Sensomat system, Aqualytic Langen. The test flasks were closed gas-tight by a measuring head. Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide. The amount of O2 consumed by the activated sludge was calculated from the decrease of pressure in the reaction vessel.
Identification: Each test unit was uniquely identified with the study num
ber, treatment and replicate number.

Test Conditions
Surrounding Type: Climatisedroom
Temperature: 22 OC
Light Conditions: Darkness
pH-Value of Test Solutions: 7.6 (measured at the start of the test)
6.9–7.7 (measured at the end of the test)

Reference substance:

benzoic acid, sodium salt

Preliminary study:

no

Test performance:

Biodegradation of Test Item
Percentage Biodegradation: The criterion for ready biodegradability under the conditions of a manometric respirometry test is the 10-day window, describing the period between reaching at least 10% degradation and 60% degradation. This period should not exceed 10 days.

Parameter:

% degradation (O2 consumption)

Value:

ca. 112

Sampling time:

28 d

Details on results:

The biodegradability of LCE07106 was 145% after 28 days without consideration of nitrification. In this case the ThCD has to be corrected. Respirometric methods with oxygen uptake as the analytical procedure may be influenced significantly by the oxygen uptake resulting from ammonium oxidation. In the case of complete nitrification, or transformation of ammonium to nitrate the degradation of LCE07106 was 112% after 28 days.
The concentration of nitrite in the test solutions was below the quantification limit (0.05 mg/L). The nitrate concentration in the controls after 28 days of incubation was 11.6 mg/L (mean). The nitrate concentration in the test item treated vessels was 25.7 mg/L (mean). Therefore, a complete nitrification occurred.
Conclusion: The degradation rate of LCE07106 did reach 60% within the 10-day window and after 28 days of incubation when nitrification is considered. According to the test guideline OECD 301, LCE07106 is considered to be readily biodegradable.

Results with reference substance:

Biodegradation in the toxicity control:
Percentage Biodegradation: In the toxicity control containing both the test item and reference 92% biodegradation was noted after 28 days of incubation under consideration of nitrification. The results are represented in Tables 5 and 6.
Conclusion: According to the test guidelines the test item can be assumed to be not inhibitory on the aerobic activated sludge micro organisms because degradation was >25% within 14 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Biodegradation of LCE07106: The degradation rate of LCE07106 under consideration of nitrification did reach 112% after 28 days of incubation. According to the guideline OECD 301, LCE07106 is considered to be readily biodegradable.

Executive summary:

Title: Ready biodegradability of LCE07106 in a manometric respirometry test

Guidelines: - Commission Directive 92/69/EEC, Method C, 4 -D of July 31, 1992: "Manometric Respirometry Test", adopted July 17, 1992

- OECD Guideline for Testing of Chemicals No. 301 F: "Ready biodegradability: manometric respirometry test", adopted July 17, 1992

Materials and methods

Test item: LCE07106; Lot No.: 07152.00018; Type: Mixture of three different amino acid N-coco acyl derivatives in aqueous solution. Purity: Nitrogen content: 3.2%; dry matter: 52.5%; chloride content: 0.7%

Test species: Aerobic activated sludge (micro-organisms from a domestic wastewater treatment plant) was supplied by the sewage works of Darmstadt, Germany.

Test design: The test item LCE07106 was investigated for its ready biodegradability in a manometric respirometry test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the micro-organisms during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

Endpoints: Degradation rate of test item calculated by the oxygen consumption of the aerobic activated sludge microorganisms after 28 days of incubation.

Test Item Loading rate: 103 mg/L corresponding to an oxygen demand of about 88 mg/L (ThCDNH4)

Reference item: Sodium benzoate

Reference Item Loading Rate: 102 mg/L corresponding to an oxygen demand of about 170 mg/L (ThODNH4)

Test conditions : 22 °C, darkness

Results

Biodegradation of LCE07106: The degradation rate of LCE07106 under consideration of nitrification did reach 112% after 28 days of incubation. According to the guideline OECD 301, LCE07106 is considered to be readily biodegradable.

Biodegradation of Sodium Benzoate: The reference item sodium benzoate was sufficiently degraded to 92% after 28 days of incubation thus confirming the suitability of the aerobic activated sludge inoculum used.

Biodegradation of the Toxicity Control: In the toxicity control containing both, the test item and the reference item sodium benzoate, 92% biodegradation was reached after 28 days of incubation under consideration of nitrification. Thus, the test item can be assumed to be not inhibitory to the aerobic activated sludge micro organisms.

Description of key information

Biodegradation of LCE07106: The degradation rate of LCE07106 under consideration of nitrification did reach 112% after 28 days of incubation. According to the guideline OECD 301, LCE07106 is considered to be readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable